In gay society there are several "social" rankings, much like traditional Hindu Castes, that form Homo-Society. At the top of these rankings is the classification Parade Gay. This means you are so gay that not only are you in the closet but the clothes in that closet are described as "fabulous". Put simply, you are so gay that you could be featured in a parade, hence Parade Gay.

Myles:"Dude I fucking love the band Queen"
Trey: "Bro Queen was super Parade Gay"
Myles:"No they weren't"
Trey: "Yes they were and therefore so are you"